1. Field of the Invention
The present invention relates to a network system, terminal device and network server, and more particularly, is suitably applied to the network system, terminal device and network server for specifying the terminal device that is being used by the user who uses various terminal devices.
2. Description of the Related Art
Heretofore, there has been a system that offers various informations to the user terminal device, i.e., the personal computer, from the information providing means, i.e., the internet service provider (ISP) via the network such as internet.
In such system, the user operating the personal computer, by entering the identification (ID) and password for connecting to the service provider into the personal computer, the personal computer receives an authentication for receiving information from the service provider using the input ID and password.
In the conventional network system, such as shown in FIG. 1, a personal computer 2 is connected to the telephone line 4 via a modem 3, and a server 5B of the service provider 5 is connected to the telephone line 4 via an access server 5A.
Moreover, a network 8 constructed such as by the local area network (LAN) in the company is connected to the server 5B of the service provider 5 via Internet 7. In this case the personal computer 8B of the network 8 is connected to the Internet 7 via the firewall 8A, thus preventing the invasion of the third party into the network 8 from the outside.
However, in such system, the user had to use the mail address, connecting telephone number or ID properly in each network depending on when he uses the network 8 of the company, the service provider 5 using his personal computer 2 in his home and when he uses the portable telephone (not shown in Fig.).
Furthermore, if the user has contracts with the plural number of providers, it is necessary for the user to use the mail address, connecting telephone number or the authenticated ID in each provider properly, and it caused a problem in usability.
Furthermore, in the conventional system, when the user was connected to the network by using either one (television, portable telephone, personal digital assistance (PDA), etc) from among various terminals, it was difficult to specify the user in the network.